1. Field of the Invention
Example embodiments of the present invention relate to a method of growing carbon nanotubes, and more particularly, to a method of growing single-walled carbon nanotubes at a relatively low temperature using H2O plasma.
2. Description of the Related Art
Carbon nanotubes (CNTs) are a carbon allotrope which makes up a large amount of carbon existing on the earth. CNTs are materials in which one carbon is bonded to another carbon atom in a hexagonal honeycomb pattern and which forms a tube shape. The diameter of the tube may be on the order of several nanometers (nm=one billionth of a meter). CNTs may have excellent mechanical characteristics, electrical selectivity, excellent field emission characteristics, and/or high-efficiency hydrogen storage medium characteristics and are well-known as useful materials.
CNTs whose graphite sheet is rolled in a nano-sized diameter may have a sp2 bond structure. Such CNTs may exhibit the electrical characteristics of a conductor or a semiconductor depending on the rolled angle and/or shape of the graphite sheet. CNTs may be classified into single-walled nanotubes (SWNTs) or multi-walled nanotubes (MWNTs) according to the number of combinations that form their walls. Further, bundled nanotubes in which several SWNTs are combined with one another may be referred to as rope nanotubes.
CNTs may be manufactured using high synthesis technology. High synthesis technology may include arc-discharge, laser vaporization, plasma enhanced chemical vapor deposition, thermal chemical vapor deposition, electrolysis, and/or flame synthesis. CNTs may have high electrical characteristics and thus can be used to manufacture a semiconductor device, for example, a CMOS. In general, a process of manufacturing a semiconductor device, for example, a CMOS and an integration process should be performed at as low a temperature as possible, for example, less than 500° C. to reduce defects in the semiconductor device. However, if the CNTs are grown at a temperature less than 500° C. using a conventional CNT synthesis method, a large amount of impurity, for example, amorphous carbon may be generated and defective CNTs may be grown. Due to the defective CNTs, the characteristics and performance of the semiconductor device containing them may be degraded.